1. Technical Field
The present disclosure is related to automotive radar systems and, in particular, to an apparatus and method for detecting and correcting for blockage of an automotive radar sensor.
2. Discussion of Related Art
In automotive radar systems, it is desirable to know when the radar sensor is blocked by debris, such as dirt, snow, ice, etc. Sensor blockage attenuates the transmitted and received signal such that objects in the field of view are no longer detectable. It is also important to alert the driver when the sensor is blocked so that the driver does not rely on the radar system while a sensor is blocked, and so that the driver can intervene and clear the debris from the sensor to restore performance of the system.
Declaring a sensor blockage based on the absence of radar signal processing detections is a relatively straightforward means of determining sensor blockage with minimal additional processing time or resources. One drawback of this approach is that it is difficult to distinguish the blocked case from the case in which there are relatively few or no objects large enough to create detections in the field of view of a sensor that is not blocked and is functioning properly. This situation can occur, for example, when the automobile in which the system is operating is passing through a desert.